Tourette Syndrome (TS) is a neurobehavioral disorder characterized by motor and vocal tics. Tics begin in childhood, and wax and wane in severity over time. TS can be associated with considerable distress, and social, academic and vocational impairment. Once considered rare, the prevalence of TS is currently estimated to be 0.8%. The exact cause of TS is unknown with both genetic and environmental factors implicated in its etiology. Research in TS has increased dramatically over the past four years, as have important advances in clinical care. Funding is requested for partial support of the 4th International Scientific & Clinical Symposium on Tourette Syndrome to be held June 25-27, 2004 at the Cleveland Clinic Foundation. It should be noted that the Tourette Syndrome Association (TSA) co-sponsored with the NIMH and NINDS the three previous International Scientific and Clinical Symposia on Tourette Syndrome. The first was in 1981, followed a decade later in 1991 and again in 1999. These symposia have served as the central forum for updating basic and clinical researchers in current research findings. This symposium will also set the agenda for future TS research efforts and clinical care. Convening the 4th Symposium in 2004 is both timely and important. Since the last symposium in 1999 we have seen a substantial increase in TS scientific publications, TS research funding, as well as advances in clinical management of this disorder. The new scientific findings are relevant to both the biological underpinnings of TS as well as to new and refined approaches to clinical care. The sponsoring organization, the TSA, has contributed greatly to the rapid advances in TS research and importantly, its dissemination. TSA has a very successful research award program. Since 1984 the TSA has funded 252 investigators for a total 8.3 million dollars. Many of the new research findings to be presented at the proposed Symposium result directly from past or current TSA-funding and active facilitation of large collaborative research consortia in genetics, neuroimaging, clinical trials and the behavioral sciences. The TSA has a broad agenda for the dissemination of research findings. The 4th International Scientific and Clinical Symposium is part of a planned effort to identify current research advances, disseminate them within the scientific community, and establish networks of basic and clinical scientists. [unreadable] [unreadable]